Cross-layer CQI feedback window adaptation for OFDMA systems under feedback budget constraint

In this paper, we propose an adaptive feedback reduction scheme FWA (Feedback Window Adaptation) for OFDMA systems with limited feedback budget. The FWA algorithm adapts channel quality indicator (CQI) feedback rate for each mobile station (MS) exploiting the signaling of MAC layer automatic repeat request (ARQ) protocol and users application profile. We applied this FWA algorithm in two feedback mechanisms namely prediction and interval based feedback (PBF and IBF) schemes. We also developed a mathematical model to derive performance metric of both integrated schemes in terms of probability of adapting feedback window. Simulation results compare the performance of FWA combined to IBF and PBF schemes with non-FWA schemes which demonstrates the performance improvement in downlink throughput and MAC frame loss rate.